Japanese students studying international law at Waseda University in Tokyo have held a mock trial on Russia's invasion of Ukraine.

In March, the International Court of Justice issued a provisional order for Russia to immediately suspend its military action in Ukraine after Kyiv filed a suit asserting that Russia had no lawful basis for military action.

Using the ruling as a reference, the students prepared statements.

A student pretending to represent Ukraine said Russia justified its invasion as an exercise of the right to collective self-defense in response to the Ukrainian government's attacks on the Donetsk and Luhansk regions in eastern Ukraine.

The student argued that because those self-proclaimed independent states are not members of the United Nations, Russia's claim of collective self-defense is baseless under international law.

A student pretending to represent Russia argued that the International Court of Justice has no jurisdiction over the case.

One of the students who observed the trial said it's important for them to consider the arguments presented by both sides logically rather than emotionally and reach their own conclusions.

Kawai Reiko, a senior member of the student group, said it's important to understand international law to make a logical judgement on what acts are wrong and why. She said she wants people to understand the issue legally and make their own decisions.